1. Field of the Invention
This invention relates to an electronic timepiece and more particularly to a multifunction digital electronic timepiece wherein at least one part of the time counting function system comprises a static counter and wherein the time counting action and multifunction action are executed in another part which includes a read only memory, referred to as ROM, and a random access memory, referred to as RAM.
Recently, with advancements made in electronic technology, electronic timepieces, especially digital electronic timepieces, have become increasingly more popular on the market. Today, a multifunction digital timepiece, a world timepiece, and a timepiece having a calculator are available.
In order to commercially market these new types of timepieces, it is necessary to speed up and be flexible with respect to product planning, circuit design and the manufacture of ICs.
2. Description of the Prior Art
In consideration of the above aspects, it is desirable that a one chip IC be capable of performing a plurality of functions. Such an IC may include a time counter which has cascade-connected static type counter and a counter for a stop watch connected therewith such as described in U.S. Pat. No. 3,757,509 or a counter for an alarm.
As another example, a shift register can be used in place of the above mentioned counter as disclosed in U.S. Pat. No. 3,988,886. In the former case, although the counter exhibits low power dissipation by using a static counter, the area occupied by the IC chip is apt to be large.
In the latter case, which is referred to as the dynamic type system, the area occupied by the IC chip tends to be small but the current consumption is apt to increase. Moreover, with respect to the speed up and flexibility of the circuit design and IC manufacture, the former and latter cases are both undesirable. In order to eliminate the above defects, an integrated watch having a random access memory combined with a programmable logic array is under development such as described, for example, in U.S. Pat. No. 4,063,409.
However, such an integrated watch is disadvantageous because it has high current consumption since the circuit acts as high speed in response to a high frequency signal in the case of displaying (1/10) seconds, and (1/100) seconds.